1. Field of the Invention
The present disclosure relates to a manufacturing method of a core using an inorganic binder, a core manufactured thereby, a manufacturing method of a casting product with a core using an inorganic binder, a casting product manufactured thereby, and a manufacturing system of a core using an inorganic binder.
2. Description of the Related Art
Korean casting foundry industry has greatly contributed to all kinds of industries including shipbuilding industry, auto-parts industry, industrial machine industry, construction machine industry, and the like. Although the casting foundry industry is an important basic industry indispensable for the development of national industry, the current environment surrounding the casting foundry industry, such as environmental problems, price fluctuations in subsidiary materials, policies, lack of manpower, and the like, is not very good. Above all, the environmental problems have been set as a priority to be solved. Currently, in the casting industry, environmental pollution has been improved in order to block discharge of environmental pollutants generated during a metal dissolution process, a core manufacturing process, and a casting process. However, since the casting industry has been regulated in greenhouse gas emission by the Muskie Act, the Kyoto Protocol, and the like, a method for getting rid of discharge of basic pollutants and a technical method for reduction in energy consumption, improvement in working environment, and greening of manufacturing sites have been urgently needed.
Generally, a core used in the casting industry is produced by mixing sand and an organic binder and curing the mixture with a core making machine and a mold. FIG. 1 is a flowchart illustrating a manufacturing process of a core and a casting product using an organic binder according to the prior art.
However, as illustrated in FIG. 1, if a core is manufactured by using an organic binder, environmental pollution is caused by the organic binder and energy consumption is increased as a curing process using a heater proceeds, resulting in a decrease in life of a mold. Furthermore, if a casting process is performed with the core manufactured by using the organic binder, a core gas is generated during the casting process, resulting in deterioration in quality of a casting product, a decrease in life of the mold, and environment pollution.
Accordingly, there is a need for development of a new binder as a substitute for a conventional organic binder in response to the requests for improvement in quality of a casting product, securing of price competitiveness, and strengthening of environmental regulations. Currently, a study for developing an inorganic binder which is an eco-friendly substance with high quality and low price has been conducted.
However, if a core is manufactured by using an inorganic binder, a curing process can be performed at a low temperature and a toxic substance is not generated, and, thus, a working environment is kept in a good condition. Furthermore, just a small amount of a gas is generated during a manufacturing process of a core and a casting process, and, thus, defects in casting are reduced, and there is no need to install an anti-environmental pollution system, and, thus, manufacturing costs can be reduced. However, the inorganic binder may cause deterioration in quality of the core due to its hygroscopic property and sand burning phenomenon.
Accordingly, the inventors of the present disclosure have tried to satisfy the above-mentioned technical demands, and finally completed the present disclosure by improving a process and developing a manufacturing method of a core and a casting product improved in hygroscopic property and sand burning phenomenon by using an inorganic binder which is improved in property such as water resistance, strength, and castability.